When a shopper takes a breath before tackling a favorite row of in-line shops, top-notch air quality and high-tech chilling stations are likely to go unnoticed. If heating, ventilation and air conditioning (HVAC) systems are undetectable by shoppers, industry professionals say the center's HVAC is doing its job well.

And if HVAC systems are operating well, it is likely to be the center's operations manager throwing switches behind the curtain. Four industry professionals -- Jim Riley, building manager for Norfolk, Va.-based Goodman Segar Hogan Hoffler; Dan Tatum, national engineering and construction services director for Insignia Commercial Group Inc., Greenville, S.C.; Ed Callahan, operations director for Hanover Mall in Hanover, Mass.; and John Genovese, vice president of real estate, The Macerich Co., Santa Monica, Calif. -- contribute their thoughts on how HVAC systems have changed with environmental restrictions, new mall design and increased traffic.

Preventive Medicine HVAC systems not only keep center temperature in a comfortably conditioned zone, but they also have a hand in filtration, flow control, energy savings and overall safety. In the minds of many industrites, HVAC systems represent an essential and expensive asset -- one that can comprise a large portion of any center's operations budget.

What is the first place to turn to preserve the often expensive HVAC investment? Not surprisingly, all interviewed for this article were quick to underscore preventive maintenance as the key to HVAC operational longevity.

"It's the same old adage: 'You pay me now, or you pay me later,'" says Goodman Segar's Riley, adding that adhering to HVAC product manufacturers' guidelines is essential to long lasting operation. "'Later' usually ends up costing the management companies a whole lot more [when it comes to HVAC]," he says. "It depends on the system, but if it's a big mall where there are a lot of equipment costs, [the mall needs] to perform preventive maintenance per the manufacturer's instructions to get the maximum life out of the equipment."

Insignia's Tatum agrees, adding that frequency of maintenance and correct implementation also are essential. "Preventive maintenance can make a difference of 50 percent in HVAC efficiency," he says. "It's the key to any system. Oil analysis, refrigerator and vibration analysis are included in the evaluation of the chiller, which should be serviced quarterly and annually, with different check points at those service times."

Callahan, operations director for Hanover Mall (owned by S.R. Weiner & Associates, Chestnut Hill, Mass.) notes that he will call for unscheduled HVAC evaluations at the sign of even a minor HVAC problem. He treats HVAC systems as an asset, and therefore must be treated with frequent, knowledgeable care.

"I have units up there that range anywhere from a replacement cost of $7,000 to $15,000," he says. "If we're not maintaining them, their lifespan will not be as long as it is supposed to be. Down the road, why should I have to replace something that hasn't been maintained properly, when I could have used that money for better capital items?

"We have the responsibility of providing a nice climate in our malls," he adds. "If we don't ensure through preventive maintenance that every unit is operating correctly, we will be unable to provide a nice, comfortable facility [for our shoppers]."

Creature comforts pose challenges Interviewees note that even the best maintained HVAC system can often be taxed by today's shopping center creature comforts. Skylights, enlarged food courts, expansive hallways and intricate common areas have become standard in many of the nation's shopping destinations, and they are often added in center renovation projects. Mall HVAC planning and implementation, they say, must compensate for these HVAC-unfriendly characteristics.

"If you have an existing mall and you decide you want skylights installed, then that's going to totally change the heat loads within the mall, and it will force you to make sure your system has sufficient capacity," says Macerich's Genovese.

Tatum notes that skylights should be viewed as another way in which a center's humidity and heat levels can fluctuate. "We treat [a skylight] like a window," he says. "In other words, you have factors that you have to calculate into your design for the heat load that's transmitted through [windows]. You must do the same thing for skylights. And since skylights can allow the temperature to rise, we can lose our dehumidification, which makes the center a pretty muggy place to be."

Callahan points out that, although skylights can tax air conditioning, they also can cause welcome -- if unpredictable -- savings in wintertime center heating. "Skylights certainly add to the summer heat load, but conversely, they can help out in the wintertime months," he says. "They can actually add significant warmth and comfort to the mall, which creates less of a burden on heating."

Some of the more unique architectural elements in food courts, says Genovese, pose challenges to HVAC operation. "In some of the current food court incarnations, [developers] are going for a more dramatic spatial design," he says. "[The design translates to] larger traffic volume and higher ceilings, which is obviously going to affect the area's HVAC loads."

"The growth of the food court has really challenged us," agrees Tatum. "The increased cooking and the heat that's gained is extremely high. Before, there was just a sandwich shop and a deli; now they house huge steak houses. Food courts are five times larger than they were five years ago, which in turn translates to a higher concentration of people.

Genovese notes that centers can keep a food court cozy by putting the area on its own HVAC zone. "[Operators should design their] HVAC systems in food courts to reflect the increased requirements," he says. "Putting the food area on its own separate zone from the rest of the mall helps to keep odor and heat better contained."

"Special events are another issue that we have to consider," says Tatum, adding that the increased traffic load causes fluctuations in HVAC needs. "We've got these large, open mall areas that, on different occasions, support huge people loads. HVAC's mechanical systems must be designed so that it has the capacity to cool or heat successfully for these special events."

Learning the ABCs of CFCs Historically, as heating or cooling loads have grown, so has the transmission of environmentally damaging chloroflurorocarbons (CFCs). With environmentally friendly refrigeration systems now becoming commonplace, HVAC's release of greenhouse gasses is lessened.

According to Jim Cox, government affairs director in the Washington, D.C., office of American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), Atlanta, demand for the environmentally friendly CFCs is likely to grow as the supply of conventional CFCs wanes. He says the shopping center industry has three choices: keep using environmentally harmful refrigerants until supply forces conversion; convert existing systems to use safer refrigerants; or purchase new machines that already incorporate newer technology.

Cox urges HVAC operators and owners to be methodical in choosing HVAC technology, as it is likely to be a long-term investment. "[Mall owners and managers] should contact equipment manufacturers and listen carefully to what products they offer," he says. "Stopping global warming [through commercial HVAC systems] may not be a regulation, but it should still be a consideration for the future."

Operations managers are taking CFCs seriously in future planning. "The CFC issue is a big thing now," says Tatum. "I am spending a lot of my time looking at properties that have CFC chillers [and trying to] determine if a retrofit is appropriate. Since you typically lose 15 percent of capacity when you do a retrofit... you may want to examine [the option of] purchasing a brand new chiller."

Genovese notes that, since many mall owners will be faced with converting existing systems to non-ozone depleting CFCs, the CFC issue will not lose relevance. "Obviously it's a challenge because it's a departure from the way things were operated in the past," he says, adding that each property requires a customized approach to changes in CFC-producing equipment.

"The critical issue is to know the regulations and the time frame as they pertain to your portfolio, and in particular, your specific asset," Genovese continues. "Each system is different in the way it is run, so you really have to evaluate them on an asset-by-asset basis."

Riley notes that an impending CFC regulation changeover is a hot button issue and will continue to have impact on HVAC systems in the coming years and beyond. "It's a big issue and an expensive one that's still on the table," he says.

Planning ahead Interviewees agree that, whether in the case of renovation or new construction, HVAC design must piggyback any construction plan, long before dirt is turned. "The best bang for your buck is going to come in the design phase, and a lot of attention has to be spent up front before the system is installed," Riley says. He adds that anticipating future changes in center design will keep HVAC design flexible and at the ready.

"[The immediate design concern is] the initial build out," he says. "But things are destined to change as you go down the road. Therefore, you want to make sure that your HVAC equipment is flexible enough to adapt to the changing layout of the mall."

Tatum notes that partially occupied centers can be of particular concern in HVAC operation. "There are many concerns when you aren't fully leased," he says. "If you've got an empty space beside you that's not being heated or cooled, then you've got additional loads that must be accounted for."

"The up-front design is one of the most important issues facing HVAC implementation," says Riley, adding that, despite proven results from early planning, HVAC design does not always start on square one with center planning. "In theory, that's the way it's supposed to be done, but it doesn't always turn out that way."

For the future, the buzzwords for HVAC professionals are efficiency, efficiency, efficiency. Tatum says the industry has already come a long way in reducing cost and increasing efficiency, with more successes likely to come. "We make our strives in technology," he says. "[The average usage rate for HVAC equipment is] down to approximately .53 kilowatts per hour, whereas five years ago, a regional mall would be at about 1 kwh."

According to Riley, a higher level of efficiency is gained through the use of energy management systems (see Shopping Center World, February 1997, page 24). "A lot more time is being spent on the design of new facilities to save money and to have more efficient HVAC," he says. "Energy management systems are being looked at [by the industry] all the time."

Although invisible to shoppers, HVAC can pose an ongoing challenge for operations professionals. Tatum cautions against cutting corners; the industry, he says, has already made and will continue to make great strides in cost and energy savings.

"New technology is definitely the way we're going to continue to achieve efficiency in our systems," says Tatum. "It doesn't just mean cutting corners; it's just being smarter in the way we operate."

Kohler Co. Natural gas generator model 180RZ from Kohler, Wis.-based Kohler Co. uses permanent magnet excitation and relies on its DEC-3 microprocessor controller to monitor the product's set functions.

SureAir HVAC maintenance management services from Stamford, Conn.-based SureAir include preventive maintenance inspections, technical repairs and 24-hour emergency response. Plumbing, electric, glass, gates and grilles, illuminated signage, locks, refrigeration, asbestos, and site surveys also are covered.

Lightstat Inc. The Lightstat(R) model TMD thermostat from Winsted, Conn.-based Lightstat Inc. includes automatic setback, flexible pre-condition periods and random restart after setback or power failure. Also included is a 3-minute, "minimum on -- minimum off" time delay for air conditioning, heating and fan outputs.

Illinova Energy Partners The Utility Manager(TM) Tool Kit software from Oak Brook, Ill.-based Illinova Energy Partners forecasts energy usage at organization, facility or account levels; reveals facility costs by square footage or customized performance benchmarks; analyzes utility rates and savings opportunities; and generates reports. It is Windows(TM) compatible.

Siemens Energy & Automation Inc. The Sentron Transient Protection System from Alpharetta, Ga.-based Siemens Energy & Automation Inc. is a surge protector with line-to-neutral, line-to-ground and neutral-to-ground protection settings. Each Metal Oxide Varistor (MOV) is individually fused at 200K Amperes Interrupting Capacity (AIC) in the line-to-ground and line-to-neutral modes. An audible alarm and an LED indicator for voltage and diagnostic monitoring are standard.

Xencom Systems Inc. Xencom System from Dallas-based Xencom Systems Inc. allows menu-driven programming for demand shedding and cycling, temperature control, alarm reporting, energy accounting and cost allocations, traffic and security monitoring, and maintenance scheduling.

Roth Bros. Inc. Services from Youngstown, Ohio-based Roth Bros. Inc. include HVAC construction and retrofit, installation and maintenance of energy management systems, national HVAC service, roofing installation and maintenance, and facilities automation.

Carrier Corp. The 39T central station air handler from Syracuse, N.Y.-based Carrier Corp. is available in capacities ranging from 2,700 cfm to 55,000 cfm. It has flanged and gasketed modular components (available in single or sectioned assembly); 16-gauge, pre-painted enamel steel cabinets; sloped condensation pans; slide-out coils; and maintenance doors on both sides of the assembly. Automated, demand-controlled ventilation (controlled by integrated sensors that assess human traffic levels) is optional.

Honeywell Inc. The 16000 series air purification system from Honeywell Inc., Commercial Air Products, Hagerstown, Md., can be a stand-alone or ductable system for capturing airborne contaminants. It may be installed above ceilings, and it provides a maximum filtration of 99.97% HEPA.